Abstract:

The cherry tomato cultivar‘Zheyingfen 1’，known for its abundant fruit flavor，was chosen as the experimental subject. The technique employed in this study involved the utilization of headspace solid phase microextraction coupled with gas chromatography-mass spectrometry. The present study aimed to compare and analyze the compositions，contents，and variations of volatile organic compounds（VOCs）in fruits subjected to humic acid treatment（control）apply water to the root and leaf surface；root and leaf application：humic acid is applied to both root and leaf surface；root application：humic acid on root and water on leaf surface；leaf application：root application of water，leaf surface application of humic acid. A comprehensive analysis revealed the detection of a total of 15 categories and 340 distinct types of VOCs. In comparison to water control，the contents of VOCs in fruits exhibited a relative increase of 49.3%，25.6%，and 14.4% when humic acid was applied to the leaves，roots，and leaves respectively. Moreover，the contents of aldehydes in fruits significantly increased with both root and leaf application of humic acid，whereas the contents of terpenes were significantly elevated solely with root application. The statistical analysis of differential VOCs revealed that，in comparison to the control group，the up-regulated VOCs resulting from the application of humic acid to both roots and leaves，solely to roots，and solely to leaves were 153，147，and 13，respectively. These values accounted for 97.5%，97.4% and 81.3% of the total differential VOCs. Notably，the differential VOCs observed in the combined root and leaf application and the sole root application were significantly greater than those observed in the sole leaf application. The examination of sensory flavor attributes revealed that the application of humic acid to both the root and leaf of tomato plants resulted in an augmentation of the sweet flavor characteristics in the fruits. Conversely，solely applying humic acid to either the root or leaf led to an enhancement of the fruity flavor characteristics. The findings from the principal component analysis indicate that the aroma attributes of tomato fruits following humic acid treatment are not primarily governed by a few VOCs with substantial relative content or high relative odor activity value. Instead，they are influenced by the interplay of multiple VOCs，resulting in distinct aroma profiles. Consequently，the application of humic acid treatment，particularly through root and leaf administration，exerts a significant impact on the composition and relative content of VOCs in tomato fruits，thereby enhancing their flavor quality.

Key words: Solanum lycopersicum var. cerasiforme, humic acid treatment, volatile organic compounds, relative content, sensory flavor characteristics